Short or broken off fingernails can be extended by fingernail tips which are secured to the natural nails by plastic materials which can cure or harden upon radiation with ultraviolet (UV) light. Reference is made to the descriptive literature issued by Lee Pharmaceuticals "LEE UV NAILS" for attachment of fingernail tips. U.S. Pat. No. 4,058,442, Lee et al, and issued to Lee Pharmaceuticals, as well as German Patent Disclosure Document DE-OS No. 25 53 138 describe tips and the plastic material in order to treat the transition regions between the natural and the artificial nail tips.
Normally, to fit an artificial tip on a natural nail, the natural nail is shaped to be round, for example by an emery board, and the tip, which at its underside has a small projection fitting against the round natural fingernail is then placed thereon and adhered by plastic adhesives. The tip which, at the upper side, merges or tapers against the upper side of the natural fingernail then must be treated in order to provide for a smooth appearance and prevent rough spots, ridges or steps. To provide a smooth surface, plastic material is repeatedly applied and, between each application of plastic material, the prior surface is cured or hardened by exposing the nails to a source of UV radiation. Hand polishing and smoothing, for example by an emery board, is also carried out.
It is customary to extend all the nails of one hand in respective steps and then curing all the nails during one curing step. The curing apparatus thus must be so arranged that it spans all five fingers, to cure all five nails in one radiation exposure. The radiation apparatus should be so arranged that it provides uniform radiation to all the nails on the fingers, both with respect to the left as well as with respect to the right hand. The results obtained by known apparatus are, unfortunately, not always uniform with regard to applied radiation, and consequent curing of the plastic material. It is desirable to use as few radiation sources as possible and to irradiate only those regions which require radiation, that is, to provide UV radiation only in the regions of the nails of the fingers. The apparatus should be suitable to treat nails of fingers of widely different sizes.
Various types of radiation apparatus have been propose German Utility Model No. 85 13 789 describes an apparatus in which a base plate is provided above which a plurality of radiation lamps are arranged, the entire structure being retained within a tunnel-shaped housing. Low pressure discharge lamps, such as UV emitting fluorescent lamps, extend into the tunnel, axially, and parallel with respect to each other in the longitudinal direction of the housing, that is, for example essentially parallel to the middle finger of the hand of a user. The lamps irradiate with wave lengths of between about 320 nm to 325 nm. Other lamps may be used which preferably have somewhat longer wave length of, for example, 360 nm to 450 nm in order to harden or cure artificial nail plastic materials.
The technical bulletin 7070 of Lee Pharmaceuticals, above referred to, entitle "LEE UV NAILS", also describes a radiation apparatus to harden artificial nails which, basically, is similar to the apparatus above described with reference to the German Utility Model No. 85 13 789. A plurality of radiation sources are located in a housing, spaced from each other and from a base plate on which the hand of the user can be placed. The hand of the user is introduced into the housing through a slit in a forward wall thereof.
German Utility Model No. 86 09 293 utilizes four elongated radiation lamps which are located above a base plate and form an irradiation tongue. The general structure is similar to that described in the above referred-to German Utility Model No. 85 13 789, and includes the additional feature that the interior space is readily accessible by flipping upwardly the upper portion of the housing about a rear transverse shaft. The irradiation sources are secured to the base plate so that, even if the cover is lifted up, they do not tilt with the cover and remain in position spaced from the base plate. The publication "TAMI NAIL LIGHT SYSTEM" of the company TAMARA COSMETIC of Munich, Fed. Rep. Germany, illustrates a curing apparatus which, in its general construction, conforms essentially to that described in the German Utility Model No. 86 09 293.